C12900 Copper vs. ASTM B685 Alloy

C12900 copper belongs to the copper alloys classification, while ASTM B685 alloy belongs to the otherwise unclassified metals. They have 40% of their average alloy composition in common. There are 17 material properties with values for both materials. Properties with values for just one material (13, in this case) are not shown.

For each property being compared, the top bar is C12900 copper and the bottom bar is ASTM B685 alloy.

UNS C12900 Fire-Refined Silver-Bearing Tough Pitch Copper ASTM B685 Palladium-Copper Electrical Contact Alloy

Metric UnitsUS Customary Units

Mechanical Properties

Elastic (Young's, Tensile) Modulus, GPa		120
Elastic (Young's, Tensile) Modulus, GPa		120

Poisson's Ratio		0.34
Poisson's Ratio		0.37

Shear Modulus, GPa		43
Shear Modulus, GPa		43

Tensile Strength: Ultimate (UTS), MPa		220 to 420
Tensile Strength: Ultimate (UTS), MPa		660 to 1060

Thermal Properties

Latent Heat of Fusion, J/g		210
Latent Heat of Fusion, J/g		180

Melting Completion (Liquidus), °C		1080
Melting Completion (Liquidus), °C		1230

Melting Onset (Solidus), °C		1030
Melting Onset (Solidus), °C		1200

Specific Heat Capacity, J/kg-K		390
Specific Heat Capacity, J/kg-K		300

Thermal Expansion, µm/m-K		17
Thermal Expansion, µm/m-K		14

Electrical Properties

Electrical Conductivity: Equal Volume, % IACS		98
Electrical Conductivity: Equal Volume, % IACS		5.0

Electrical Conductivity: Equal Weight (Specific), % IACS		98
Electrical Conductivity: Equal Weight (Specific), % IACS		4.1

Otherwise Unclassified Properties

Density, g/cm³		9.0
Density, g/cm³		11

Common Calculations

Stiffness to Weight: Axial, points		7.2
Stiffness to Weight: Axial, points		6.1

Stiffness to Weight: Bending, points		18
Stiffness to Weight: Bending, points		15

Strength to Weight: Axial, points		6.8 to 13
Strength to Weight: Axial, points		17 to 27

Strength to Weight: Bending, points		9.1 to 14
Strength to Weight: Bending, points		16 to 21

Thermal Shock Resistance, points		7.8 to 15
Thermal Shock Resistance, points		28 to 46

Alloy Composition

Aluminum (Al), %		0
Aluminum (Al), %		0 to 0.0050

Antimony (Sb), %		0 to 0.0030
Antimony (Sb), %		0

Arsenic (As), %		0 to 0.012
Arsenic (As), %		0

Bismuth (Bi), %		0 to 0.0030
Bismuth (Bi), %		0

Cadmium (Cd), %		0
Cadmium (Cd), %		0 to 0.050

Copper (Cu), %		99.88 to 100
Copper (Cu), %		39.5 to 40.5

Iron (Fe), %		0
Iron (Fe), %		0 to 0.050

Lead (Pb), %		0 to 0.0040
Lead (Pb), %		0 to 0.030

Nickel (Ni), %		0 to 0.050
Nickel (Ni), %		0

Palladium (Pd), %		0
Palladium (Pd), %		59 to 60.5

Silver (Ag), %		0 to 0.054
Silver (Ag), %		0 to 0.1

Tellurium (Te), %		0 to 0.025
Tellurium (Te), %		0

Zinc (Zn), %		0
Zinc (Zn), %		0 to 0.060

Residuals, %		0
Residuals, %		0 to 0.2